1. Field of the Invention
The present invention relates to a filter for tobacco smoking and, more specifically, to a flavor-containing filter.
2. Description of the Prior Art
Tobacco products generally contain one or more flavors as additives for enhancement of the smoking flavor. Flavors which are added to tobacco products are normally categorized into two groups; a primary flavor group for casing sources, and a secondary flavor group for top flavors. These flavors are often added to shredded tobacco by means of a direct spraying technique which takes place during the process of manufacturing cigars or cigarettes.
However, during the manufacturing process, many of the flavors of the secondary group are susceptible to volatilization and deterioration caused by heat and the surrounding air, which results in the flavoring being of reduced effectiveness. In addition, volatilization and deterioration of flavor can also occur during storage of the final product. In order to avoid such drawbacks, secondary flavors are often used in the form of inclusion in porous particles or of encapsulation in microcapsules, with the aim of protecting them against the effects of heat and air, and thus preventing volatilization and deterioration thereof.
Use of particles or microcapsules which contain or encapsulate flavors of the secondary group as additives to shredded tobacco, has been proposed in Japanese Patent Disclosure No. 48/23997. However, use of encapsuled flavors as described in the above cited patent disclosure is accompanied by a variety of problems which occur in the process of manufacturing tobacco products. These problems include the fact that a more complex method than spraying is required for adding the microcapsules, and that the added microcapsules tend to separate from shredded tobacco and generate dust. Moreover, use of encapsuled flavors as described in the above document entails drawbacks such as denaturation of the flavors due to the microcapsules being burnt at the time of smoking, and the generation of unpleasant smells as a result of the burning of the film materials constituting the microcapsules. Since these drawbacks pose unacceptable hazards in terms of the health of smokers, the method set forth in this disclosure has found no 20 practical applications to date.